In known, conventional methods for transporting logs in the form of saw timber or pulp wood from felling site to consumer, the processing, i.e. felling, limbing and cutting of the logs, is usually carried out by means of a cross-country harvester, whereupon a separate cross-country forwarder collects the logs and transports them up to a landing preferably along a main haul road, which can be reached by a road vehicle. The individual logs are loaded on the forwarder one by one or in small bundles by means of a crane which is mounted on the forwarder and which is also used for unloading the logs at the landing. Here the logs are sometimes unloaded in large stacks (frequently containing hundreds of cubic meters or more) from which the logs are also loaded in bundles onto the road vehicle, however by means of a crane mounted on the road vehicle or by a separate loader.
One drawback of the transporting and handling technique described above is that both producer and consumer can form only a vague idea of the character of the logs felled and transported to the landing, with regard to the total volume, thickness, length and partial volumes of the different tree species in the lot. The different stacks are roughly divided roughly into saw timber and pulp wood, but within the scope of these classification criteria, highly varying partial volumes of spruce and pine, thick and thin as well as long and short logs may occur in e.g. a saw timber stack. This is most unsatisfactory in so far as a certain saw mill is, on a certain occasion, perhaps mainly interested in e.g. thick and long logs of a determined tree species, while other saw mills may have other preferences.
The known transporting technique is further ineffective in so far as reloading from the cross-country vehicle to the road vehicle is time-consuming and thus expensive, since both unloading from the cross-country vehicle and loading on the road vehicle is carried out in bundles by means of fairly small cranes. Furthermore it is a biologically detrimental condition that the wood remains at the landing for a more or less long period, before being collected by the road vehicle. It may particularly happen that certain log quantities which have been felled early, remain for a longer period than other quantities felled on a later occasion. In practice, each such delay results in drought cracks and insect attacks which deteriorate the quality, especially of saw timber.